Abstract: Diabetic peripheral neuropathy (DPN) is one of the chronic complications of diabetes. Professor LI Leyu applied the theory that all six meridians possess exterior syndromes to treat DPN. He proposed that the core pathogenesis of this condition stems fundamentally from prolonged diabetes and deficiency of visceral fluids and blood, with external wind-cold pathogens invading the six meridians and causing meridian impediment-obstruction as the branch, constituting a syndrome characterized by deficiency complicated with exterior excess. Based on this, he established a six-meridian syndrome differentiation system for DPN, which categorizes the six major exterior syndromes—Taiyang, Yangming, Shaoyang, Taiyin, Jueyin, and Shaoyin, and differentiates the syndromes of cold, heat, deficiency, and excess. He flexibly employed modified classical formulas such as Guizhi Decoction, Danggui Sini Decoction,and Fuzi Decoction,with the core therapeutic principles of eliminating pathogenic factors and reinforcing healthy qi to unblock meridians. Clinically proven cases have demonstrated the stability of this treatment approach,thus providing a novel perspective for traditional Chinese medicine management of DPN.